Hot glass, especially when formed into various shapes in the manufacture of glass containers, is susceptible to being damaged by contact with glass processing equipment. Most of the equipment with which hot glass comes in contact in the hot end process area during the process of manufacturing containers such as glass bottles is fabricated from metallic materials such as stainless steel and other alloys. However, in certain areas of the hot end processing of glass containers, it has been found desirable to utilize non-metallic materials such as asbestos, plastics, or carbon fibers.
One such application is in the plates which rest upon the air plenums of glass container-forming machines known as dead plates. These plates are fabricated with a multiplicity of apertures to permit the flow of air from the plenum. Adjustable air flow causes the formed glass bottles to be suspended above the plenum and to cool the bottles sufficiently for contact handling. The plates must be heat resistant and non-absorbent with respect to the oils used in bottle production.
Of the materials which have previously been used for dead plates, asbestos is undesirable for environmental reasons. Plastics suitable for use at the high temperatures encountered in the hot end process area must be specially formulated. Stainless steel and other metal alloys used for dead plates, while otherwise satisfactory, are subject to failure due to warpage, bending, gouging or breakage.
Metallic dead plates may cause checking by momentary contact with the hot formed bottles. Checking is the formation of imperceptible cracks due to sudden localized heat transfer or thermal shock.
In addition to ordinary wear of dead plates, damage can occur during crashes in the processing line. Where a dead plate is damaged and requires replacement, there is a loss of production while the production line is shut down until the dead plate can be replaced and the work station where the dead plate is located can be brought back on line at operating temperatures.
It would, therefore, be desirable to provide a dead plate which can be easily repaired or replaced in the event of wear or damage.